Tapered push rod



Sept 1966 v. J. D] MATTEO, SR, ETAL 3,272,190

TAPERED PUSH ROD Filed July 21, 1965 V/hcen/ J D/Maffeo, Sn Vincent J D/Mafleo, Jr

Bar/o/a DiMof/eo 1N VENTOKS aofizn.

WW fim United States Patent 3,272,190 TAPERED PUSH ROD Vincent J. Di Matteo, Sr., Los Angeles, Calif., and Vincent J. Di Matteo, Jr., and Bartolo Di Matteo, both of 7415 8th Ave., Los Angeles, Calif.; said Vincent J. Di Matteo, Sr., assignor to said Vincent J. Di Matteo, Jr., and said Bartolo Di Matteo Filed July 21, 1965, Ser. No. 473,782 9 Claims. (Cl. 123-90) This invention relates to a novel push rod construction and more specifically to the construction of push rods for internal combustion engines having overhead valves and utilizing push rods to actuate the intake and exhaust valves thereof.

Although conventional solid rod-like push rods have been utilized satisfactorily in the past for operating the overhead valves of in-line six-cylinder engines and slow speed V-8 engines, the newer types of higher speed sixcylinder and V-8 engines require the use of tubular push rods in order to provide a means for reducing the total weight of the reciprocating parts of the valve train. Still further, the newest high speed engines also use tubular push rods but in the upper r.p.m. ranges of these high speed engines the conventional tubular push rods, which are substantially cylindrical in configuration and of a constant diameter throughout their entire length, bow or bend resulting in incorrect valve timing and valve float.

The push rod of the instant invention is of tubular configuration to maintain its weight at a minimum and is tapered throughout substantially its entire length in order to reduce any tendency of the push rod to bend under high stresses and during high engine speeds. This type of construction greatly reduces the tendency of the push rod to bend during operation of the associated engine at high speeds and the utilization of a tubular push rod minimizes valve floatduring high speed operation of the associated engine.

In addition, the wall thickness of the tubular push rod of the instant invention tapers from the minor diameter end portion of the push rod to the major diameter end portion of the push rod in order to insure sufiicient strength at each point spaced longitudinally along the push rod to prevent bending due to extreme stresses at high engine speed. By having the wall thickness of the tubular push rod greater than the minor diameter end portion of the push rod and by reducing the wall thickness at the major diameter end portion of the push rod, maximum effective strength of the push rod is obtained while maintaining the push rod weight at a minimum. Still further, the use of a tapered push rod which gradually tapers in wall thickness from one end to the other reduces the possibility of lateral vibration occurring during high speed operation which might tend to result in the push rod bending.

The main object of this invention is to provide a push rod for high speed internal combustion engines and constructed in a manner which greatly resists the tendency of the push rod to bend while operating under high stresses and at high speed.

A further object of this invention, in accordance with the immediately preceding object, is to provide a push rod for internal combustion engines and in accordance with the preceding objects which may be readily constructed in a manner so as to comprise a ready replacement for various types of push rods presently in use and without modifications to the internal combustion engines in which the push rods are to be used.

A still further object of this invention is to provide a push rod for high speed engines constructed in a manner maintaining the weight of the push rod at a minimum and reducing the possibility of vibration or bending of the push rod under high stresses at high engine speeds.

A final object of this invention to be specifically enumerated herein is to provide a push rod in accordance with the preceding objects which will conform to conventional forms of manufacture, be of simple construction and easy to use so as to provide a device that will be economically feasible, long lasting and relatively trouble free in operation.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout, and in which:

FIGURE 1 is a transverse vertical sectional view taken upon a plane passing through a conventional form of V-8 internal combustion engine and showing the push rod of the instant invention in operative positions;

FIGURE 2 is a side-elevational view of the push rod with portions thereof being broken away and shown in vertical section; and

FIGURE 3 is an enlarged horizontal sectional view taken substantially upon the plane indicated by section line 3-3 of FIGURE 2.

Referring now more specifically to the drawings, the numeral 10 generally designates an internal combustion engine. The engine 10 is an eight-cylinder engine with the cylinders thereof arranged in banks of four cylinders with the banks of cylinders disposed at relative to each other. The engine 10 includes a conventional cam shaft 12 and valve lifters 14. In addition, the engine 10 includes poppet valves 16 and rocker arm "assemblies 18 for actuation of the poppet valves 16. The push rods of the instant invention are generally designated by the reference numeral 20 and are disposed between each lifter 14 and the corresponding rocker arm 18 in order to effect inverse reciprocation of the poppet valves 16 in response to reciprocation of the lifters 14.

The push rod 20 includes an elongated tubular main body portion 22 which is circular in cross-section throughout its entire length. The main body portion 22 tapers in diameter from its lower major diameter end 24 toward its upper minor diameter end 26. Solid end members 28 and 30 are utilized to close the lower and upper major and minor diameter end portions of the main body portion 22 and it may be seen that the solid end members 23 and 30 include diametrically reduced shank portions 32 and 34, respectively. The shank portions 32 and 34 are snugly telescoped into the major and minor diameter end portions of the main body portion 22 and secured therein in any convenient manner. The end faces of the major and minor diameter end portions of the tubular main body portion 22 abut against the shoulders 36 and 38, respectively, thereby allowing an axial thrust applied to one end of the push rod 20 to be directly transmitted to the other end of the push rod.

The diametric taper of the push rod 20 is constant throughout the entire length of the main body portion 22 and from FIGURE 2 of the drawings it may be seen that the wall thickness of the tubular main body portion 22 is tapered from the minor diameter end portion of the main body portion 22 to the major diameter end portion thereof. In this manner, the smaller diameter end portion of the main body portion 22 has a greater wall thickness than the larger diameter end portion of the main body portion 22 and it is to be further noted that the taper of the wall thickness of the main body portion 22 is substantially constant throughout its entire length.

The solid end members 28 and 30 are of course constructed of hardened material and the material utilized in the main body portion 22 of the push rod 20 may be selected from those materials available to give optimum performance with a minimum tendency to bend and a long life expectancy.

The operation of the push rod 20 is deemed to be apparent from the foregoing and it has been found through tests that the push rods 20 operate satisfactorily without bending or vibrating appreciably under the extreme axial loads of approximately 3000 lbs. when utilized in high speed racing engines, the normal loads on conventional push rods utilized in slow speed internal combustion engines being in the neighborhood of 400 lbs. axial thrust.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention as claimed.

What is claimed as new is as follows:

1. An enlongated tapered push rod, said push rod including a long tubular main body portion substantially evenly tapered throughout substantially its entire length, the opposite ends of said push rod including short terminal end sections at least substantially closing the opposite ends of said main body portion and adapted to have longitudinal thrusts applied thereto, and wherein the wall thickness of said main body portion substantially evenly tapers in thickness from one end portion to the other end portion thereof.

2. The combination of claim 1 wherein said short terminal end sections comprise substantially solid end members secured to the opposite ends of said main body portion.

3. The combination of claim 2 wherein said solid end members include shank portions telescoped in the corresponding ends of said main body portion.

4. The combination of claim 3 wherein said shank portions comprise diametrically reduced portions of said end members defining annular and generally radially extending circumferential shoulders against which the corresponding end faces of said tubular main body portion are abutted.

5. The combination of claim 1 wherein the wall thickness of said main body portion tapers substantially evenly in thickness from the minor diameter end portion thereof to the major diameter end portion thereof.

6. The combination of claim 5 wherein said short terminal end sections comprise substantially solid end members secured to the opposite ends of said main body portion, said solid end members including shank portions telescoped in the corresponding ends of said main body portion, said shank portions comprising diametrically reduced portions of said end members defining annular and generally radially extending circumferential shoulders against which the corresponding end faces of said tubular main body portion are abutted.

7. A tapered push rod for use in actuating poppet valves, said push rod including an elongated tubular main body portion which is circular in cross section throughout its entire length and which includes at least a center section thereof extending substantially the entire length of said body portion and which is evenly tapered throughout its entire longitudinal extent, the opposite ends of said main body portion including end closing sections closing the ends of said tubular main body portion and adapted to have longitudinal thrusts applied thereto, the wall thickness of said tubular main body portion tapers in thickness from the minor diameter end portion to the major diameter end portion of said center section of said main body portion.

8. The combination of claim 7 wherein said end closing sections comprise solid end members secured to and closing the opposite ends of said main body portion.

9. The combination of claim 8 wherein said solid end members include shank portions telescoped in the corresponding ends of said main body portion, said shank portions comprising diametrically reduced portions of said end members defining annular and generally radially extending circumferential shoulders against which the corresponding end faces of said tubular main body portion are abutted.

References Cited by the Examiner UNITED STATES PATENTS 2,025,836 12/1935 Treiber 123-90 2,743,712 5/1956 Hulsing 123-90 2,863,431 12/1958 Marietti 123-90 2,897,805 8/1959 Etzler 123-90 3,034,488 5/1962 Reiners 123-90 MARK NEWMAN, Primary Examiner.

AL LAWRENCE SMITH, Examin r. 

1. AN ENLONGATED TAPERED PUSH ROD, SAID PUSH ROD INCLUDING A LONG TUBULAR MAIN BODY PORTION SUBSTANTIALLY EVENLY TAPERED THROUGHOUT SUBSTANTIALLY ITS ENTIRE LENGTH THE OPPOSITE ENDS OF SAID PUSH ROD INCLUDING SHORT TERMINAL END SECTIONS AT LEAST SUBSTANTIALLY CLOSING THE OPPOSITE ENDS OF SAID MAIN BODY PORTION AND ADAPTED TO HAVE LONGITUDINAL THRUSTS APPLIED THERETO, AND WHEREIN THE WALL THICKNESS OF SAID MAIN BODY PORTION SUBSTANTIALLY EVENLY TAPERS IN THICKNESS FROM ONE END PORTION TO THE OTHER END PORTION THEREOF. 